During medical procedures fluids of different types need to be injected into human tissue and vascular structures. Various medical procedures require a radiographic image of a vascular structure to be obtained by injecting radiographic contrast material through a procedure catheter into a hollow anatomical structure, such as a blood vessel, artery, vein, or heart chamber. X-rays are then passed through the region of the body in which the contrast material was injected. The X-rays are absorbed by the contrast material causing a radiographic outline or image of the hollow anatomical structure containing the contrast material. The x-ray images of the hollow anatomical structures filled with the contrast material are usually recorded on memory, such as on film or videotape, and displayed on a fluoroscope monitor. When a series of different fluids are to be administered, or a series of injections are required, it is often necessary to flush one fluid from the injection line before the next fluid is administered. For example, during angioplasty, the procedure catheter is often flushed with saline before and/or after the addition of contrast solution. Further, it is also necessary to purge any injection lines of air and to prevent the reintroduction of air into the lines.
The injection of the contrast or other fluids can be performed either manually or automatically. In both injection procedures, a procedure catheter is inserted into a hollow anatomical structure, which in turn is connected to a fluid line leading to a valve or manifold which is in fluid communication with an injector or syringe. The plunger of the injector or syringe is then either manually or automatically depressed to inject fluid through the fluid line, through the procedure catheter, and into the patient.
The most commonly used apparatus for these types of procedures involves the connection of a catheter to a valve or manifold having a number of stopcock valves. Movement of fluids between selected fluid sources, other apparatus, and to the procedure catheter and patient is typically accomplished with a syringe or other manual injection device. The physician is typically required to selectively open and close the valves or manifold to control the source, path and direction of the fluid flow during a procedure. The physician may also be required to draw fluid, take a blood sample, remove waste, inject medication, or flush fluid out of the injection device repeatedly during a procedure.
Because a physician is required to manipulate a number of stopcock valves during a procedure to achieve a desired flow path to or from the procedure catheter, it takes training to learn how to properly operate one of the prior art manifolds. Further, because it may not be immediately evident from looking at the manifold which way the fluid is flowing, it is easy to make an improper connection resulting in no unintended fluid delivery into the patient. Because a number of stopcock valves are involved in the prior art manifolds, the handles must be small so as to not cause interference with one another. However, the small handles can be difficult to grasp and manipulate. Additionally, physicians often develop a “tactile feel” for infusing fluids through catheters with the syringe or other injection device, maintaining the infusion pressure within desired pressure ranges to avoid damaging catheters, vessel dissection, damaging catheter balloons or unintentional damage to any hollow anatomical structures while still achieving flows sufficient for contrast-enhanced imaging.
In certain situations, it is necessary to dilute the concentration of contrast being injected into a patient. For example, in those patients with renal insufficiency incapable of processing concentrated contrast through their system, or in cases where a large amount of contrast is used, such as complicated coronary interventions (PTCA) or peripheral (PTA) cases with runoffs, direct injections of contrasts, are not desired. Accordingly, it may be necessary to mix the contrasts and saline prior to injection to arrive at the appropriate dilution percentage. The goal is to obtain a dilution percentage that is safe for the patient and still provides a clear image. Such processes are necessarily slow and are currently difficult to achieve using known injectors in the art. There is a need in the art to easily mix contrast and saline in-line and control the dilatation of the concentration of contrast being injection; thereby preventing unnecessary contrast from entering the patient's body and also reducing overall contrast used allowing for a cost saving by the hospital.
To address these issues, an improved automated fluid management system has been developed and is disclosed herein. Automated injection system disclosed in this application advantageously provide physicians with a simplified process for selecting fluid sources to inject into hollow anatomical structures at high pressures up to 1400, and typically between 900-1200 psi.
Traditional injection procedures for coronary injections as commonly known in the art may include the use of a manifold, as described above, for controlled injections of both saline and contrast. If high volume injections are then required the manifold may be removed and the user may have to then attached an automated injectors to the procedure catheter. Therefore, a need in the art exists, of which this invention satisfies, for an automated injector that can be used with controlled injection of both saline and contrast. An advantage of this system is incorporating the ability to perform controlled injections historically done by manifolds together the ability to simultaneously automate injection of contrast, saline, or a mixture of both in-lines at high pressures.